The invention relates generally to an arrangement for and a method of transferring sheet-like articles.
More particularly, the invention relates to an arrangement for and a method of transferring sheets of photosensitive material.
In a more specific aspect, the invention relates to an arrangement for and a method of removing sheets of film, especially X-ray film, from a container.
The German Offenlegungsschrift No. 31 22 585 discloses an arrangement for removing film, particularly X-ray film, from an upright container having a discharge opening for withdrawal of the film. The container accommodates sheets of film having different sizes. The sheets are stacked one behind the other in upright positions. The container has an internal lateral abutment and a lateral edge of each sheet of film is brought into contact with the abutment before withdrawal of the sheet from the container. This insures that all of the sheets are in the same position upon being removed from the container. Removal of the sheets from the container is effected by a suction device having an effective width which approximates or equals the width of the smallest film. The suction device removes the sheets of film from the container and transfers these to a conveyor.
A problem with the above arrangement stems from the fact that the width of the largest sheet of film may be between five and seven times the effective width of the suction device. In this regard, the suction device has a plurality of suction heads and the term "effective width of the suction device" is intended to mean the distance between the two outermost suction heads. The suction device is mounted in such a fashion that a large sheet of film is gripped at only one side thereof, that is, the suction device grips one side but not the other of a large sheet of film. As a result, large sheets of film are frequently fed into the conveyor obliquely rather than straight. This can occur, for instance, when a sheet of film is grasped by the conveyor before the vacuum in the suction device has been completely destroyed. Thus, the portion of the film held by the suction device may be hindered or prevented from entering the conveyor by the vacuum which remains in the suction device. On the other hand, the portion of the film which is not gripped by the suction device is relatively unrestricted against being drawn into the conveyor. The moment arm obtained in this manner causes the film to rotate so that the film assumes an oblique position.